function [ ] = mx_eyelink_data_switch( )
%MX_EYELINK_DATA_SWITCH Sets what data from tracker will be accepted and 
% placed in queue.
%
% Remarks:
% This does not start the tracker recording, and so can be used with 
% eyelink_broadcast_open(). It also does not clear old data from the queue. The
% data is set with a bitwise OR of these flags: RECORD_LINK_SAMPLES - send 
% samples on link. RECORD_LINK_EVENTS - send events on link.
% Parameters:
% flags 	Bitwise OR flags.
% Returns:
% 0 if OK else link error.
%
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% Copyright Eduardo Aponte 2013
% aponteeduardo@gmail.com